Air–sea gas exchange in the North Atlantic: 3He/SF6 experiment during GasEx-98

Abstract

GasEx-98 was the first open-ocean process study where gas transfer velocity measurements were made with several robust techniques, including airside eddy covariance of CO2 and deliberate injection of 3He and SF6. While the CO2 eddy covariance results have been fully analysed and publicised, leading to a boom in the use of this technique in the marine environment, the 3He/SF6 results have not received the same level of analysis. Here, based on new approaches that we have developed to analyse 3He/SF6 data in the subsequent years, we revisit the 3He/SF6 dual tracer results from GasEx-98 and show that they are consistent with the results from other parts of the coastal and open ocean, and that they are in agreement with current parameterisations between wind speed and gas exchange for slightly soluble gases over the ocean at intermediate wind speeds.

Keywords

• air–sea gas exchange
• 3He/SF6 dual tracer technique
• North Atlantic